The DigRF (Digital Radio Frequency) interface is a digital serial interface, which replaces the analog interface in previous generation mobile handset architectures supporting a variety of 3GPP air standards. A common standard for interfacing is the DigRF standard specified by the Mobile Industry Processor Interface (MIPI) Alliance. A current form of this standard is version v3.09. A new release of the DigRF standard—in the following also being referred to as called DigRF v4—is under specification (see mipi.org).
The physical layer of the DigRF connects an RF-IC (radio frequency integrated circuit) and a BB-IC (base band integrated circuit) with a seven wire interface. Independent transmit (Tx) and receive (Rx) differential signal pairs allow for concurrent bi-directional communication between a RF-IC and a BB-IC. In telecommunications in particular, it is often the case that those parts of the signal which are at low frequencies are converted up to higher frequencies for transmission purposes, since it may be difficult for communications media to pass low frequencies due to attenuation behaviour. The original, low frequency components, may be referred to as the baseband signal. Typically, the new, high-frequency copy is referred to as the RF or radio frequency signal. Again referring to DigRF, signals may be provided as the timing references for digital serial data transmission and recovery. The DigRF standard defines two basic packet types. Control packets are typically generated by the BB-IC for the purpose of configuring the RF-IC. Control packets are also utilized to communicate status between the RF-IC and the BB-IC. Digital input/output data is transferred between the RF-IC and the BB-IC in DigRF data packets.
Conventionally, DigRF technology may lack sufficient flexibility for a user.